Generally, MEMS is provided with a plurality of components, which consume electrical power, such as a micro sensor, a micro actuator, a micro-pump, a microprocessor and the like. These components can be installed in a restricted space due to their micro-scale size. Although such components can be driven with a very small quantity of electrical power (compared to that of a macro system), it is necessary to supply a stable electrical power for reliable operations of the components.
A large capacity battery or a micro fuel cell can be used as a power source for supplying power to the MEMS. However, such battery or fuel cell needs to be replaced with a new one after a predetermined period of time. In addition, when the MEMS requires only low power consumption or is used as a disposable device, a self-generation type generator, which is inexpensive and does not require the use of a battery, may be employed. Specifically, a typical self-generation type generator includes a generator adapted to use a temperature difference between high and low temperatures, a generator based on Seebeck effect and the like. Such type of generator is superior compared to the power source comprising a battery or fuel cells.
One example of a generator, which is based on the Seebeck effect, is a micro power generator comprising a thermoelectric module.
Among the self-generation type generators, one example of the generator that uses the temperature difference is disclosed in Korean Patent Laid-Open Publication No. 2003-0058420, which was filed by the applicant of the present invention. Such laid-open publication discloses that a membrane compresses a piezoelectric material through the expansion of fluid contacting a heat source, thereby generating electrical currents. Also, a closed-loop type micro generator is disclosed in Korean Patent Laid-Open Publication No. 2003-0093663, which was also filed by the applicant of the present invention. In such laid-open publication, a magnet is moved in a coil by means of fluid, which circulates in a close-loop micro channel and is boiled or condensed by a temperature difference. However, although various types of generators as mentioned above have been continuously developed and introduced, such conventional generators are deficient in that they have low efficiency and output in terms of power generation, and can only typically operate within restricted temperature ranges and circumstances.